Exercise chair



FIG. 1 is a perspective view of an exercise chair showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view thereof, the side opposite being a mirror image;

FIG. 4 is a rear elevational view thereof; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for an exercise chair, as shown and described. 